is it legal to cut off a muzzle break, and thread the barrel to put a flash hider on,of course keeping the barrel length above 16"?  thanks for answers.also,could i cut out the metal in between the holes on the muzzle break ,to make it look like a flash hider?

Yes

you have to keep the parts count in mind, though.  if it was a US muzzle brake, then more than likely you'll need a US made flashhider.

So it is legal as long as parts count is kept in check.  Does anyone have any advice as how to remove the muzzle break from a Century G3 clone.  It appears to be a simple grind away to find the pin and knock it out, but what position is the pin located at? I have tried a Google search and over at hkweaponsystems.com they report it to be in the 6 o'clock position, although pics from anyone who has done this would be nice to make it a bit more idiot proof.

Additionally, are there any sources for a US made flash hider?  I am able to find HK made flash hiders although I don't want the BATF(E) knocking on my door for a parts count violation.

No complaints from me about the factory muzzle break, although it seems that nobody wants to occupy any of the range tables adjacent to me when I'm shooting, something about head splitting muzzle blast.

Thanks in advance, just looking for a little bit of insight.

IGF makes US flash hiders. I have an extra if they are out.

There is a pin silver-soldered in the FH. You will be throwing it away after removing, it so let her rip. I covered the exposed barrel just in case of a slip. My 'spring' clip was soldered, along with a blind pin which shook loose once I got the solder off it. Afterwards, unscrew the brake(counter-clockwise), apply anti-sieze and replace a new FH.

Beware of minimum barrel length if the brake was a very long one on a short barrel.